You will have to cut them freehand. If you make them bold enough you may be able to cut out each letter and lay the paper on your gumpaste and cut it out. Then just use fondant tools to make lines or grooves in them that match the font you choose. Honestly I would try piping it. Print out the right size and lay a sheet of clear acetate over top and practice piping till you are happy with it. You may even be able to do that in RI and let it dry and then glue the letters where you want them.